Senator Obama's "veep vetter," James Johnson, is former CEO of Fannie Mae Corporation, and faces questions about home loans he received from Countrywide Financial, a partner of Fannie Mae, and one of the firms caught up in the subprime mortgage debacle. According to The Wall Street Journal, Mr. Johnson received more than $2 million in home loans from Countrywide that may have had unusually low interest rates.

Now, Obama faces a major diversion from his message of change and getting away from "politics as usual." At a Monitor breakfast on Wednesday, Chairman Dean played down Johnson's role in the campaign and hit back hard at the GOP.

"Johnson doesn't get paid; he's a volunteer," Dean said. "Secondly, since it was a Republican-planted story, obviously it's fair to say that the Republicans are hypocrites, and they are. The guy who's running the McCain campaign is a lobbyist who's on leave, Rick Davis. Then they take plenty of lobbyist money, the RNC [Republican National Committee] takes lobbyist money. So I mean, what is this? This is nuts."

Obama has pledged to take no donations from lobbyists, and, as de facto leader of the Democratic Party, has the Democratic National Committee on board with the same policy. The Republicans have not followed suit. But with the Johnson controversy swirling now for several days, Obama's attempt at presenting a "clean" campaign has been sullied.

Dean sought to shift the focus back to the GOP.

"The distinction is that Barack Obama does not have any lobbyists on his paid staff," he said. "None. Zero. And John McCain does."

Dean also portrayed Democratic unease about November as a positive. All the predictive political models portend an excellent year for the Democrats, given the nation's economic woes and the Iraq war. But as polls remain close between Obama and the presumptive Republican nominee, Senator McCain, especially in battleground states, some Democrats are worried that Obama could lose.

"You know what, I'm actually thrilled they're nervous," Dean said. "I think it's about time. Last spring, there was this feeling of confidence that we were just going to roll through everything, and that's how you lose elections. So I'm just delighted that Democrats are really nervous about whether they can win or not. Just delighted. It's the most important thing that's happened, other than the fact that we finally have a nominee."